One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to estimate when it's the best time to plant delphinium by checking out the USDA zone info for Trussville.

Planting Calendar for Delphinium

Frost tolerance for delphinium:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since delphinium do ok in moderate cold you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant delphinium in Trussville is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant delphinium and expect a good harvest is probably August. Any later than that and your delphinium may not have a chance to fully mature. Starting your delphinium indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Trussville the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

Since the USDA zone info for Trussville is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Trussville you get a frost after April 15 be ready to cover your delphinium if you have a late frost.

USDA Zone Info for Trussville

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Trussville

You may be interested in your other planting guides for Trussville.